The specific aims are outlined: (a) To develop methods of synthesis of specific small-carborane fragments and organoboron hydride ions for incorporation into biologically active compounds which selectively localize at certain centers in living systems. (b) To prepare boron tagged metabolites for 1. cancerous tumor cell destruction, 2. study of the mechanisms of hypertensive activity, of antifungal action, and of certain coronary dilatory action. (c) A study of bonding and structure in cage boron compounds.